Two environmental groups announced this week their intent to sue the current and past owners of the Stilley swine feeding operation near Trenton if they don’t take steps to clean up the facility.

The Neuse Riverkeeper Foundation and the Waterkeeper Alliance allege that the facility is illegally discharging swine waste into groundwater, wetlands and streams that flow into the Trent River.

The farm, about 20 miles west of New Bern, confines more than 11,000 hogs for Murphy-Brown, a subsidiary of Virginia-based Smithfield Foods. Smithfield Foods was acquired by Shuanghui International Holdings Ltd., China’s largest pork producer, in September for $4.72 billion.

Jake Jacobson, vice president of the board of directors for the Neuse Riverkeeper Foundation, said the organization has been monitoring runoff from the operation for about six years. The farm has had several owners over that period, he said.

“We wanted to confirm it over a long period of time so it would be a very solid case,” he said.

The organizations have given the owner 90 days to work with them to find a solution to the problem or they will file suit under the federal Clean Water Act and the Solid Waste Disposal Act.

Jacobson said the groups’ preference is to avoid a legal confrontation.

“In this particular case, we have strongly encouraged that we want to have a conversation; we want to talk about protective measures,” he said.

Industrial-scale hog farming has been a contentious issue in Eastern North Carolina for decades, with many people complaining about the storage of hog waste in lagoons and the spraying of liquid manure on adjoining land.

In 1997, amid uproar about environmental problems in hog farming, the state slapped a temporary moratorium on new or expanded hog farms that used what is known as the lagoon-and-spray-field method.

Under the method, waste is flushed from hog barns into open-air lagoons, and the effluent is sprayed on fields.

Efforts to get a response from Smithfield Foods officials were unsuccessful.